[detectionview] support single item selection, hightlight selected items

fixtracks/widgets/detectionview.py

@@ -15,9 +15,15 @@ class Detection(QGraphicsEllipseItem):
         super().__init__(x, y, width, height)
         self.setBrush(brush)
         self.setAcceptHoverEvents(True)  # Enable hover events if needed
+        self.setFlags(QGraphicsRectItem.ItemIsSelectable)
 
     def mousePressEvent(self, event):
         self.signals.clicked.emit(self.data(0), QPointF(event.scenePos().x(), event.scenePos().y()))
+        # item = self.scene().itemAt(event.scenePos(), self.views()[0].transform())
+        
+        # if item:
+        #     item.setSelected(True)
+
         # print(f"Rectangle clicked at: {event.scenePos().x()}, {event.scenePos().y()}")
 
     def hoverEnterEvent(self, event):
@@ -54,20 +60,22 @@ class DetectionScene(QGraphicsScene):
 
     def mouseReleaseEvent(self, event):
         if event.button() == Qt.LeftButton and self.selection_rect is not None:
-            # Perform selection of items within the selection rectangle
             rect = self.selection_rect.rect()
-
-            # Remove the temporary selection rectangle
             self.removeItem(self.selection_rect)
             self.selection_rect = None
-
-            # Find all items that intersect with the selection rectangle
-            selected_items = self.items(rect, Qt.IntersectsItemShape)
-            for item in selected_items:
-                if not isinstance(item, Detection):
-                    selected_items.remove(item)
-                item.setSelected(True)  # Mark the item as selected
-            self.signals.itemsSelected.emit(selected_items)
+            if rect.width() > 0.0:
+                # Find all items that intersect with the selection rectangle
+                selected_items = self.items(rect, Qt.IntersectsItemShape)
+                for item in selected_items:
+                    if not isinstance(item, Detection):
+                        selected_items.remove(item)
+                    item.setSelected(True)  # Mark the item as selected
+                self.signals.itemsSelected.emit(selected_items)
+            else:
+                item = self.itemAt(event.scenePos(), self.views()[0].transform())
+                if item:
+                    item.setSelected(True)
+                self.signals.itemsSelected.emit(self.selectedItems())
         super().mouseReleaseEvent(event)
 
 
@@ -133,7 +141,7 @@ class DetectionView(QWidget):
 
 def main():
     def items_selected(items):
-        print(items)
+        print("items selected", items)
     
     import pickle
     import numpy as np
@@ -141,7 +149,7 @@ def main():
     from PySide6.QtWidgets import QApplication
 
     datafile = PACKAGE_ROOT / "data/merged_small.pkl"
-    imgfile = PACKAGE_ROOT / "data/merged.png"
+    imgfile = PACKAGE_ROOT / "data/merged2.png"
     print(datafile)
     with open(datafile, "rb") as f:
         df = pickle.load(f)